The objective of this proposal is to obtain partial support for a Summer Conference on 'Lipid Modifications of Proteins' to be held under the auspices of the Federation of American Societies for Experimental Biology (FASEB) from August 6 to August 11, 1995, at Copper Mountain, Colorado. The conference will be limited to about 150 scientists. There will be 9 major scientific sessions, each with 3-4 oral presentations by invited experts and speakers chosen on the basis of submitted abstracts, as well as poster sessions to encourage wider participation. Previous conferences in this area were held in 1991 and 1993 under the auspices of the American Society for Biochemistry and Molecular Biology (ASBMB); both meetings were enthusiastically received. The study of lipid-modified proteins is in a period of tremendous growth. The field has emerged from the phase of structural descriptions to one in which the enzymology and biology of these modifications are the main foci of investigation. The family of acylated and/or prenylated proteins includes the src oncogene, the Ras superfamily of small guanine nucleotide binding proteins, cell surface receptors and signal transduction molecules. In many cases the lipid modification of the protein has been shown to be critical to protein function by influencing sub-cellular location or protein-protein interactions. The more elaborate glycosylphosphatidylinositol (GPI) modification is found on a functionally diverse spectrum of mainly cell surface glycoproteins that include cell adhesion molecules important in the immune system and in development, protozoal coat proteins, and cell surface receptors. Recent work has suggested that GPI-anchored proteins may be markers of membrane structural domains that are functionally important in intracellular membrane traffic and transmembrane signalling. The biological significance of lipid-modifications of proteins is of great current interest and a conference in this area in 1995 would be useful and appropriate.